Hydrocodone/APAP pill discard after date?

I have some Vicodin left from mid-2001 when I broke my leg, well I now broke my collar bone, and have been prescribed Vicodin once again. I didn't have a chance to pick up the prescription yet, so I was wondering what the deal with "Discard after" dates are? What exactly happens to these pills after this date (the date on mine is 3-21-01). Is it ok to take these, they have been stored in the same place, in the bottle, at room temperature, for pretty much the whole time..

even though the pills are old, they still would be somewhat effective, there is nothing in there that could "hurt" you from being expired, but by all means, refill your new prescription because I think they only give you about 5 days to fill a narcotic prescription., at least in the state I live in. hope this helps a little, you could always call and ask your pharmacist.